A disk drive is disclosed comprising a disk, a head, and an actuator for actuating the head over the disk. The disk drive further comprises a state variable memory for storing a plurality of state variable sets, wherein each state variable set comprises a plurality of state variables and each state variable set corresponds to a task object. A coefficient memory for stores a plurality of coefficient sets, wherein each coefficient set comprises a plurality of coefficients and each coefficient set corresponds to a task object. A task object is executed by initializing a base state register to address a selected one of the state variable sets in the state variable memory, and initializing a base coefficient register to address a selected one of the coefficient sets in the coefficient memory.